Effectiveness of Phosphorus Solubilizing Bacteria on Enhancing Phosphorus Availability from Minjingu Phosphate Rock to Maize in Slightly Acid to Neutral Soils

Abstract

The aim of this one-year field study was to evaluate the impact of phosphorus solubilizing bacteria (PSB) on increasing the availability of phosphorus locked up in insoluble Minjingu phosphate rock for the maize crop (Zea mays L.) in high soil pH. The study was carried out during one wet season in Nghumbi and Mlali villages in Kongwa District in the Dodoma Region, Tanzania. Based on the pH of their soil and the limiting nutrients, two farms from Mlali village and five from Nghumbi village were chosen at random for field trials. To determine the fertility status, composite soil samples were collected from the chosen farms and examined in a lab. Target treatments included the application of PSB inoculum in combination with various rates of Minjingu phosphate rock (MPR) (0, 20, 30, 40, and 60 KgP ha-1) as a basal fertilizer, placed beneath maize seed and covered with a thin layer of soil. Using a fully randomised block design, the treatments were set up three times. Inadequate levels of N, P, K, and Zn were found in the research area's soil samples. Results indicated the main effect of fields’ characteristics from field No.2 had the highest yield to other fields with significantly (P< 0.001) highest grain yield being 4.4 t ha-1, biological yield of 5.6 t ha-1, and Straw P uptake of 19.63 kg ha-1. Using P or an inoculant (Mx) produced a negligible yield of grain and straw, according to the major effect of treatments. For the studied variables, none of the treatments showed any significant (P =0.427) interaction effects. An intriguing revelation that the study's maize response to native P is provided by interaction effects area is a factor of soil and amount of P released to the soil. We recommend more research on PSB for more than one season in high soil pH before ascertaining the technology to farmers.